electrical and 4x4 problems 88 S10... HELP!
 

Just picked up a sweet little 88 pickup. it has a few "issues" that i was wondering if anyone had run accross...

PO stated that the alternator had "blown up" and that since then the gauges havent worked right and the lights in the dash have been a little funky. The stay dim and everything is slightly lit. Major power fluctuations when blinkers are on.

4x4 is not engaging either. PO said it was probably the vacuum canister, but i cannot confirm that. When you pull up the stick to engage, nothing happens. I wondered if it could be related to the electrical trouble as well.

Any suggestions or wisdom are greatly appreciated. You guys haven't failed me yet!

Re: electrical and 4x4 problems 88 S10... HELP!
 

www.autozone.com has wiring digrams. I would replace all the wiring from the alternator. A power spike or reverse polarity connection will blow up wires and fuses. I'm not familiar with 4X4. Yes, the vacuum activated switch is a common problem.

Re: electrical and 4x4 problems 88 S10... HELP!
 

I hope that you mean the wiring that directly connects to the alternator And not everything in the truck. I did think about reworking the ground and maybe upgrading the thickness of the wire. is that the kind of stuff you were suggesting?

Re: electrical and 4x4 problems 88 S10... HELP!
 

The vacuum actuator is a common problem on these trucks. Is this a 2.8L? If so, the vacuum actuator is easy to get too... One way to check it, is to feed direct vacuum to it from the vacuum ball (I've put a T in the line to feed mine before). If the front axle engages, then the vacuum actuator is fine the issue is the t-case switch. If the front axle does not engage then either te vacuum actator is bad or the cable to the front axle is siezed.

Re: electrical and 4x4 problems 88 S10... HELP!
 

Thanks man I appreciate the input. I will give that fix a try. So your saying to use the vacuum ball to test it. So just hook up the supply to the ball to the cannister? Great thought thanks a million!

Re: electrical and 4x4 problems 88 S10... HELP!
 

And yes its a 2.8 5spd

Re: electrical and 4x4 problems 88 S10... HELP!
 

Yup, mine was a 4.3L, so the actuator was under the battery tray. My t-case switch was bad, so it wasn't sending vacuum to the actuator. For a quick fix, I cut the line running to the vacuum ball, put in a T and then fed a line to the vacuum actuator. When I didn't want 4wd, I disconnected that line and plugged the T... good ol' farm fix.

On the 2.8Ls, the vacuum actuator is on the passenger's side fender - so much easier to get to!